Router Bit Speed Chart: RPM by Bit Diameter

A three inch panel raising bit turning at 22,000 rpm has a cutting edge moving at about 107 miles an hour. The same router with a quarter inch straight bit in it, at the same 22,000 rpm, moves its edge at 16. That is the whole reason a speed chart exists: the dial on the router sets rotations, but the wood is cut by the outer edge, and the outer edge of a big bit covers far more ground per turn than a small one. What follows is the chart, the reason two charts you find online will hand you two different numbers for the same bit, and the feed rate half of the setting that most speed charts leave out.

Run bits up to 1 inch across at 18,000 to 24,000 rpm, 1 to 2 inch bits at 12,000 to 18,000, 2 to 2-1/2 inch bits at 10,000 to 16,000, and anything over 2-1/2 inches at 8,000 to 12,000. Those upper figures are the rated ceiling and the lower figures are where the cut is cleanest. Check the rating printed on your own bit before setting the dial.

• Speed drops as diameter rises, because edge speed rises with diameter at any fixed rpm.
• The number on your bit package is a maximum rating, not a recommendation. It is a ceiling.
• Charts disagree because some publish the safety ceiling and others publish the best cutting speed.
• Bits over about 1-1/2 inches across belong in a table-mounted variable-speed router, never handheld.
• A single-speed router runs at 24,000 to 30,000 rpm and is rated for small bits only.
• Feed rate is the other half of the setting, and a slow feed burns wood at any correct rpm.
• Burn marks mean the edge is rubbing rather than cutting: feed faster or slow the router down.

The Router Bit Speed Chart

In short: find your bit diameter on the left, and use the recommended column unless the bit's own rating is lower.

Two columns, because there are two honest answers. The maximum column is the speed the bit is built to survive. The recommended column is where the cut comes out clean, and it is the one to set the dial to. The edge speed column is the quantity both columns control, and it is there so you can see why the numbers fall the way they do.

The edge speed column is arithmetic rather than opinion, and you can check any row of it yourself with the formula further down. One thing it shows straight away: the recommended speeds are not arbitrary. They hold edge speed inside a band that widens gently as bits get bigger, instead of letting a three inch cutter run at highway speed.

Why Two Charts Give You Two Different Numbers

In short: one kind of chart publishes the safety ceiling, the other publishes the cutting speed, and neither says which it is.

This is the thing that sends people in circles. Look up a 1 inch bit and one chart says 22,000 rpm while another says 16,000. Neither is wrong. They are answering different questions.

A maximum rating comes from the bit maker and it is a structural limit. It says the carbide, the braze joint holding the carbide to the steel body, and the balance of the bit have been built to hold together up to that speed. Freud, for example, states that bits with cutting diameters up to 1 inch are rated to 24,000 rpm and are balanced to run a safe margin above the 22,000 rpm that a typical router tops out at. Exceed a rated maximum and the failure is not a poor cut, it is a piece of carbide leaving the tool.

A recommended speed is about cut quality, and it sits below the ceiling on every bit big enough for the difference to matter. It is the speed at which the edge takes a chip of a useful thickness instead of skimming the surface and generating heat.

So when two charts disagree, look at the column heading rather than the number. If the chart gives one figure per diameter and calls it a maximum, treat it as a limit you stay under. If it gives a range and calls it recommended, that is a dial setting. And in every case the rating stamped on your own bit or printed on its packaging outranks any chart on the internet, including this one, because it is the only figure that describes the specific tool in your hand.

Edge Speed Is the Number Both Columns Are Setting

In short: edge speed in feet per minute is pi times the diameter in inches times rpm, divided by 12.

Rpm on its own tells you nothing about how hard a bit is working. Edge speed, sometimes called rim or tip speed, is what the carbide experiences, and it is a two line calculation:

• Edge speed in feet per minute = 3.1416 x diameter in inches x rpm, divided by 12.
• To get miles per hour, multiply feet per minute by 60 and divide by 5,280.

Take a 2 inch bit at 12,000 rpm. That is 3.1416 x 2 x 12,000 = 75,398 inches per minute, divided by 12 for 6,283 feet per minute, which is 71 miles an hour. Now put the same bit at 22,000 rpm, a setting that is fine for a quarter inch bit: the edge goes to 131 miles an hour. Nothing about the router changed. The diameter did all of it.

This is worth being able to run yourself, because a chart cannot cover every bit. If you own a 1-3/8 inch bit and the chart jumps from 1-1/4 to 1-1/2, work out the edge speed at the two neighboring recommended settings and pick the rpm that lands between them. It takes fifteen seconds and it beats guessing.

Feed Rate Is the Other Half of the Setting

In short: rpm sets how fast the edge travels, feed rate sets how thick a chip it takes, and the second one is what burns your wood.

Almost every router speed chart stops at rpm, which leaves out the half of the equation that a beginner is more likely to get wrong. Two routers set to the same correct speed will produce a clean cut and a scorched one depending on how quickly the wood is pushed past the bit.

The mechanism is chip load, the thickness of the shaving each cutting edge removes per revolution. Freud puts it plainly in its published feed and speed guidance: a chip that is too small, or that is dust rather than a chip, cannot carry heat away from the edge, so the carbide runs hot and dulls early. A chip that is too large tears the surface. The relationship is one multiplication:

Feed rate in inches per minute = rpm x number of flutes x chip load

Freud publishes chip load figures for its carbide tipped straight and profile bits, and these are the numbers to work from. Depth of cut here is assumed to be no more than the bit diameter.

Source: Freud's published router bit feed and speed guidance. Freud notes that these are starting points for test cuts in scrap, not a warranty against breakage, and that cutting deeper than the bit diameter means reducing chip load: by at least 25 percent at twice the diameter, and by at least 50 percent at three times.

Those figures were written for machine feeding, where a controller holds an exact rate. On a hand-fed router the number still tells you something useful, once you translate it. A 1/2 inch two-flute bit at 18,000 rpm in hardwood, at a chip load of 0.009 inches, works out to 324 inches per minute. That is 5.4 inches a second, or a steady walking pace along the edge of a board. Most people who burn their work are moving at half that speed or less, hesitating over the cut. The chart above is the answer to "am I going too slow," and for most beginners the answer is yes.

If Your Router Has Only One Speed

In short: a fixed-speed router is a small-bit tool, and no technique makes it safe for a large one.

Trim routers and older fixed-base routers often have no speed dial at all. They run wide open, usually somewhere between 24,000 and 30,000 rpm. Read that against the chart above and the consequence is immediate: that speed is at or above the rated ceiling for anything larger than about 1 inch across, and far above it for a panel bit.

There is no workaround worth having. A router speed control sold as an aftermarket accessory reduces voltage rather than regulating speed, so the motor loses torque along with rpm and bogs down in exactly the heavy cut that made you want the lower speed. Cutting a big profile in many light passes does not help either, because rated speed is about what the bit survives while spinning, not about how much wood it is removing.

What does work is matching the bit to the tool you own. Fixed-speed router, bits up to about 1 inch, and take the profile in stages with smaller cutters. If the work calls for raised panels or a large rabbeting bit, that is a variable-speed router in a table, which is a real difference in capability rather than a preference. The trade-offs between owning fewer, more capable machines and a wider spread of smaller ones are covered in our guide to hand tools versus power tools, and the router sits in the broader picture of shop equipment in the woodworking machinery guide.

Reading the Cut: What Burning and Chatter Are Telling You

In short: burning is too little chip, a wavy or torn surface is too much, and both are fixed by changing feed before changing speed.

The cut itself is a better instrument than any chart, because it reports on your actual bit in your actual wood. Four things it tells you:

• Dark burn lines, and dust rather than shavings. The edge is rubbing. Feed faster first. If the burn stays at a brisk feed, the rpm is too high for the diameter and the dial comes down.
• A rippled or scalloped surface. The feed is too fast for the rpm, so each edge is taking a bite too thick to leave a flat surface. Slow the feed or raise the speed a step.
• Chatter you can feel through the handles, and a chewed edge. Usually too large a bit at too high a speed, or too much depth in one pass. Reduce the depth of cut before touching anything else.
• Tear-out on one part of the board only. That is grain direction rather than speed. Cherry, maple and figured stock tear where the grain rises toward the cutter, which is why a climb cut on a light final pass sometimes cleans up what a conventional pass would not.

Burning is also more common in some species than others regardless of setting. Cherry and hard maple scorch at settings that leave pine and poplar clean, because dense, closed-grain wood carries less heat away from the edge. The density differences that drive this are set out in the types of wood guide.

Setting Speed Without Losing a Finger

In short: unplug to change bits and speed, let the router reach full speed before it touches wood, and never start a variable-speed router at a low setting under load.

A few habits sit around the speed dial and belong with it. Unplug the router before changing a bit or a speed setting, every time, because a bit change is the moment a hand is closest to a cutter. Seat the shank fully in the collet and then back it out about a sixteenth of an inch before tightening, so the bit is not bottomed out against the collet nut.

Let the motor reach its set speed before the cutter meets the wood. A soft-start router takes a second or two to get there, and starting the cut early is a spike in load at low rpm. Feed against the rotation of the bit, which for a handheld router working the outside edge of a board means moving left to right. Inspect a bit before it goes in: a chipped edge or a dull one increases both heat and the force needed to feed, and neither improves with a change of speed. Broader guidance on guarding, dust and push technique is in our woodworking safety guide.

Router Bit Speed FAQ

What speed should a 1/2 inch router bit run at?

Around 20,000 rpm is a good starting point for a 1/2 inch straight or profile bit, and the bit will normally be rated to 24,000. Drop toward 18,000 in dense hardwood or if the cut starts to burn.

Why do router bit speed charts disagree with each other?

Because they are publishing two different things. Some charts list the maximum speed the bit is rated to survive, and others list the speed that cuts best. Both are correct for their own purpose, and the rated maximum is always the higher of the two.

Can I run a large panel raising bit in a router that has only one speed?

No. A single-speed router runs at roughly 24,000 to 30,000 rpm, which is above the rated maximum of every bit over about 1 inch across. Bits that size belong in a variable-speed router mounted in a table.

Does a faster router speed give a smoother cut?

Only up to a point. Above the bit's best range the edge spends more time rubbing than cutting, which heats the carbide, burns the wood and shortens the life of the bit. Smoothness comes from a steady feed at the right speed, not from raw rpm.

What feed rate should I use with a handheld router?

Fast enough to keep the chip a real shaving rather than dust. Freud's chip load figures work out to roughly five inches a second for a 1/2 inch two-flute bit at 18,000 rpm, which is a slow, steady walking pace along the board.